The present invention relates to a device for preventing fretting rust and the pounding-out of the bearing seat in motor systems, in the case of which a rotating radial load acts on the motor bearing, e.g., in the case of motors with a rigidly coupled load.
When electric motors are installed in machines, belts, pinions, or couplings may be used to transfer torque. In this case, the classic bearing load is a point load. With a very rigid coupling, a rotating radial load is generated, however. In most cases, the motor bearing becomes the first mechanical “weak point”. The torque generated by the rotating load therefore acts on the bearing and/or its seat until the bearing is “pounded out” after a short period of time, and “fretting rust” forms.
Fretting rust is a type of fretting wear that occurs on contact surfaces and mating surfaces. Oscillations, fine vibrations, slippage, and loose fits result in a very high mechanical surface load, due to a combination of mechanical wear and cyclic stressing. The material surface becomes fatigued and activated, and a reaction takes place with the ambient medium (air, lubricants, water, etc.). In addition, conditions become favorable for the formation of microtears, which greatly reduces the fatigue limit of the material. Fatigue failure may therefore result.
Unexamined patent application DE 198 18 634 A1 discloses a floating bearing for spindles and shafts that is mounted via support elements in the bearing seat, using an intermediate bearing.
Due to the positioning of the bearing in the bearing seat using support elements, the bearing is hardly suited to absorbing rotating radial forces and, in applications with a rigid coupling of a load, in which rotating radial forces occur repeatedly, premature bearing seat wear would occur.